24VAC transformer

Hi guys,
Newbie here and could use some guidance. I have a specialty device that uses 24VAC, I also have a custom module that spits out 12VAC. I thought it would be simple to convert 12VAC to 24VAC (60Hz) but have been unable to find a low power (10W) transformer. Any links or ideas where to get one? I see lots of 110/220 voltage converters on ebay and can rip the transformer out of one but seems like I should be able to find it stock someplace. Alternatively, if there is 12VDC to 24VAC module, that is an option if the price is low.

I think you should start by explaining what these "modules" actually are, giving Web links to them.

Most door bell transformers are 24VAC or there abouts. Same with transformers for heating/ air conditioning controls.

Paul

Hello,

First off, let me just say, don’t read and follow anything I say…

I need a 24vac power supply, shop around for doorbell transformers. For about $15.00, maybe more at your local home improvement store, you can find a transformer that when connected to 110vac outputs 8vac, 16vac, and 24vac. Using this route, you will be plugging into mains power and you must take all the precautions of doing so. If you don’t know what that means, don’t do it!

A simple google search for a 2:1 power transformer turned this up:
link

Looking at the datasheet, it looks like it will do what you want as far as AC conversion, but I just glanced at the docs…

Anyway, I don’t know what I’m talking about, I was never here and you didn’t see me.

Randy

A common 240 / 120 volt "international" transformer like you would use to run a 240V British electric razor in North America will output 24V on the 240 side if you put 12V on the 120 side.

You can just buy a 24 VAC 1.0 Amp transformer for about $10 USD Hammond Part #166JA12 from any number of distributors including Digi-Key which is one of many. Over the current you need so there will be plenty.

https://www.digikey.com/products/en?keywords=166J24

A simple Google of "24 VAC wall wart" will bring up plenty of hits also.

Additionally please define "if the price is low" my low is a $10 USD transformer. Low when used in price is relevant as my low and your low may not be the same low.

Ron

Thanks for the multiple suggestions but either I don't know how to read the spec sheet or I'm not clear in what I'm asking for. I need a 12VAC to 24VAC transformer. (not 110 to 24) .

dsmith888:
Thanks for the multiple suggestions but either I don't know how to read the spec sheet or I'm not clear in what I'm asking for. I need a 12VAC to 24VAC transformer. (not 110 to 24) .

Then just find a 240 VAC to 120 VAC control transformer (1:2 Ratio) and input your 12 VAC to the secondary side and the primary side will output your 24 VAC. Just make sure it meets your VA requirement. I seriously doubt you will find a 12 VAC to 24 VAC transformer easily or economically. It's likely just as easy and economical to get a transformer with a 24 VAC secondary and a primary of 120 or 240 VAC depending on your local mains voltage.

Ron

yes thanks can you link 120/240 low power transformer? I'm having trouble finding one.

dsmith888:
Thanks for the multiple suggestions but either I don't know how to read the spec sheet or I'm not clear in what I'm asking for. I need a 12VAC to 24VAC transformer. (not 110 to 24) .

Time for you to learn how to wind your own transformr.

Paul

dsmith888:
yes thanks can you link 120/240 low power transformer? I'm having trouble finding one.

Surely you use Ebay as a source for cheap parts. Search for:transformer 24v.

Paul

dsmith888:
I have a specialty device that uses 24VAC, I also have a custom module that spits out 12VAC.

Can you post a picture of the custom module, some use centre tap transformer secondaries?
Thanks.. Tom.. :slight_smile:

dsmith888:
yes thanks can you link 120/240 low power transformer? I'm having trouble finding one.

I have no idea where you are on the planet so have no idea where to suggest. A simple Google of 240 VAC / 120 VAC should find you some locally. That is a 2:1 ratio so you apply 12 VAC to the secondary and get 24 VAC out on the primary. Control transformers like this are very common.

Ron

revolt_randy:
you can find a transformer that when connected to 110vac outputs 8vac, 16vac, and 24vac. Using this route, you will be plugging into mains power and you must take all the precautions of doing so. If you don't know what that means, don't do it!

Normally the transformer IS the precaution. That's why most power supplies have one.

If you can find a 24 VAC transformer with a center tap and of suitable current
rating, you can drive half the winding with 12 VAC and take 24 VAC from the
total winding. (The primary winding is of no use to you.)

Thanks Herb,

That suggestion was a path I didn’t think of. I can find those transformers but it is still cheaper to find a 110/220 wall wart and rip out the transformer. I see multiple replies that the 1:2 transformer is very common but don’t know why I can’t find one. Seems like it should be readily available like mentioned by multiple folks and the many wall warts on ebay,google.

If you take the wall wart approach just make sure it's a heavy wall wart which uses a transformer like you want. Newer wall warts seem to be all pretty much a SMPS design.

Ron

dsmith888:
Thanks Herb,

That suggestion was a path I didn't think of. I can find those transformers but it is still cheaper to find a 110/220 wall wart and rip out the transformer. I see multiple replies that the 1:2 transformer is very common but don't know why I can't find one. Seems like it should be readily available like mentioned by multiple folks and the many wall warts on ebay,google.

Waste of a good wall-wart. WallWarts rated at 85-265 Volts do NOT use a transformer, they use a switcher IC like the LNK304.

As others have said, your description is quite vague, so you will get vague answers. Please respond to the very first reply to your question.

" I have a specialty device that uses 24VAC, I also have a custom module that spits out 12VAC."
What is the "device" and what is the "module"? If you want good answers, provide good information.